Proton therapy, also called proton beam therapy, is a type of radiation treatment that uses protons rather than X-rays to irradiate diseased tissue. Although this disclosure focuses on describing the invention in terms of a therapy involving a proton beam (i.e., “proton therapy”), it contemplates therapies with other suitable ion beams (i.e., “ion therapy,” generally). One advantage of therapy using high energy proton or ion particles is that their path though the tissue stops at a certain depth, depending of the energy of the particle. On their path through the tissue the particles interact with the matter of the tissue and lose energy to the matter of the tissue. Since the particles increasingly lose energy on their path through the tissue, and since the rate of energy loss is higher with decreasing energy of the particles, the particles lose most of their energy at or toward the end of their path through the matter of the tissue, right before they stop. The high energy deposition loss of charged particles at the end of their travel path through the matter of the tissue is called the “Brag Peak.” Furthermore, charged particles may be actively steered in a transverse direction (which may be described in x- and y-coordinates) of the particle travel path. By the superposition of charged particles with different energies and by specifying x- and y-positions, one can achieve better three-dimensional dose conformity than with X-ray radiation therapy.